<!DOCTYPE html>

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <button id="connect">连接</button>
  <button id="send" disabled="true">发送数据</button> <br>
  从服务端接收的数据如下: <br>
  <span id="recv"></span>
  <script>
    let connect = document.querySelector('#connect')
    let send = document.querySelector('#send')
    let recv = document.querySelector('#recv')
    let ws = null
    connect.onclick = function () {
      ws = new WebSocket('ws://localhost:9998')
      // 监听连接成功事件
      ws.onopen = () => {
        console.log('连接服务器成功了...');
        send.disabled = false
      }
      // 监听关闭连接事件
      ws.onclose = () => {
        console.log('连接服务器失败了...');
        send.disabled = true
      }
      // 监听接收数据事件
      ws.onmessage = msg => {
        console.log('接收到从服务端发送过来的数据了');
        console.log(msg);
        recv.innerHTML = msg.data
      }
    }
    send.onclick = function () {
      // ws.send(JSON.stringify({
      //   action: 'getData',
      //   socketType: 'trendData',
      //   chartName: 'trend',
      //   value: ''
      // }))
      ws.send(JSON.stringify({
        action: 'themeChange',
        socketType: 'themeChange',
        chartName: '',
        value: 'chalk'
      }))
    }
  </script>
</body>

</html>